# FAQ: Am Fm Tuning Variable Capacitor?

## How does a variable capacitor tune a radio?

This radio circuit therefore, is tuned by adjusting the capacitance of the variable capacitor to equalize the inductive and capacitive reactance for the desired resonant frequency, or in other words, to tune in the desired radio frequency.

## What is the purpose of tuning capacitor?

Variable capacitors are often used in L/C circuits to set the resonance frequency, e.g. to tune a radio (therefore it is sometimes called a tuning capacitor or tuning condenser), or as a variable reactance, e.g. for impedance matching in antenna tuners.

## Can capacitors be fixed or variable?

There are two major types of capacitors: fixed and variable. Fixed capacitors have set capacitances because the parallel sheets of metal are at a fixed distance apart, while variable capacitors have the ability to change based on manipulation of the parallel plates.

## Which capacitor is used for radio frequency tuning?

Variable Capacitor A typical variable air capacitor used in radio frequency circuits is composed of two arrays of parallel conductive plates in a single assembly.

## Which is variable capacitor?

A variable capacitor is a capacitor whose capacitance can be adjusted within a certain range. When the relative effective area between the pole metal plate or the distance between the plates is changed, its capacitance changes accordingly. It is usually used as a tuning capacitor in a radio receiving circuit.

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## Which capacitors are used for fine tuning?

Dielectric Capacitor Dielectric Capacitors are usually of the variable type were a continuous variation of capacitance is required for tuning transmitters, receivers and transistor radios.

## How do tuning capacitors work?

Tuning capacitors are popular type of variable capacitors. The rotor plates when moved into the slots of stator, they come close to form plates of a capacitor. When the rotor plates sit completely in the slots of the stator then the capacitance value is maximum and when they don’t, the capacitance value is minimum.

## Do trimmer capacitors have polarity?

The actual capacitance value can be varied between the minimum and maximum capacitance values for a given trimmer capacitor, but it can never be set to zero. It is worth noting that trimmer capacitors are not polarized.

## How do you tune a variable capacitor?

The centre pin is common to both variable capacitors. In some variable capacitors, C1 and C2 are of equal value of around 20 pF, whilst C3 and C4 are of equal value of around 160 pF. For a Crystal Radio, you use the AM radio common pin, which is the centre pin on the AM side of the capacitor, and the AM antenna pin C4.

## What is the symbol for capacitor?

The SI unit of capacitance is farad (Symbol: F ).

## What are the examples of variable capacitor?

Types of Variable Capacitors

• Tuning Capacitors.
• Trimmer Capacitors.
• Mechanical Capacitors.
• Electronic Capacitors.

## What are two applications of capacitors?

Applications of capacitors

• 1 Energy storage.
• 2 Pulsed power and weapons.
• 3 Power conditioning.
• 4 Power factor correction.
• 5 Suppression and coupling. 5.1 Signal coupling. 5.2 Decoupling.
• 6 Motor starters. 6.1 Signal processing. 6.2 Tuned circuits.
• 7 Sensing. 7.1 Changing the dielectric.
• 8 Oscillators.